Modern wireless communications systems, such as cellular or personal communication subscriber (PCS) telephone systems, are in wide use around the world. These systems generally include one or more antennas that are mounted on an associated antenna tower. Each antenna tower typically is associated with a base station.
In order to provide wireless service to a given area (service area), wireless service providers normally erect one or more antenna towers at predetermined locations within the service area. As wireless communications services have become more popular, service providers have endeavored to build out wireless communications systems to provide service to larger areas. As a result, it has become common in many communities for there to be several antenna towers dotting the landscape.
Antennas and antenna towers are subjected to demanding environmental factors, such as high winds. Typical antenna towers have been designed and constructed to provide the strength necessary to support an antenna subjected to these environmental conditions. This has meant that the typical antenna mast/tower is large, bulky and generally unappealing in appearance. Often, these antenna towers are obtrusive and contrast sharply with the surrounding environment in a negative way, and are commonly viewed by the community as “eye-sores.” This is due in part to the fact that most typical antenna towers have been constructed to provide functionality at the expense of form or aesthetics.
To address this aesthetics issue, efforts have been made in recent years to provide antenna towers, including associated support structures, which are less obtrusive to the eye and more compact in profile/structure. Unfortunately, the needs for high strength have tended to make it difficult to provide a compact structure.
As wireless communication becomes more and more ubiquitous, there is an ever-increasing demand for more antenna towers and for more equipment mounted on a single tower. This demand for greater equipment mounting on a single antenna leads to antenna towers that are bulkier, not more compact, thereby creating a tension between the need for greater capacity and the desire to make the antenna tower more compact (and therefore less obtrusive). The growing demand for greater equipment mounting on individual antenna towers also leads to a need for increased structural strength, due to the greater mass and length of the antenna complex mounted at the top of the tower. This need for increased strength also tends to lead to larger structures, as mentioned above. One approach to this dilemma has been to make the tower and associated equipment as large as desired and then to try to obscure the structure to the greatest extent possible with camouflage techniques to try to blend the tower into the surrounding environment.
Examples of known antenna systems designed to blend into the surrounding area include that shown in U.S. Pat. No. 6,122,866 to Trevor et al., for a Method and Apparatus for Concealment and Disguisement of Antenna Structures, which discloses a support structure (FIG. 1) that resembles a palm tree. U.S. Pat. No. 6,343,440 to Ayers, for Antenna Towers Having A Natural Appearance, also shows an antenna structure that is formed to appear as a palm tree (FIG. 1 and FIG. 2). The Ayers patent also shows an antenna structure formed to resemble a saguaro cactus (FIG. 17 and FIG. 18). Similarly, U.S. Pat. No. 6,434,889 to Jones, for an Antenna Support Structure With Palm Tree Skirt, shows an antenna support structure that includes a plurality of green members and a plurality of drooping members that cause the antenna support structure to resemble a living palm tree. U.S. Design Pat. No. Des. 398,612 to Juengert et al., for an Antenna Support Structure, shows an antenna support structure that strongly resembles a tree.
Other known antenna support systems that take on a somewhat compact profile are shown in U.S. Pat. No. 5,641,141 to Goodwin, for an Antenna Mounting System. In Goodwin, an antenna mounting apparatus is shown which includes three antenna members. The antenna members are positioned so as to provide adequate communications within a selected radial distance. Another antenna system having a somewhat compact profile is shown in U.S. Pat. No. 5,880,701 to Bhame et. al., for an Enclosed Wireless Telecommunications Antenna. Bhame shows an antenna module that is configured to support three dual polarization antenna panels.
At least as early as January 2001, EMS Wireless (a division of EMS Technologies, Inc.), the assignee of the present application, was offering for sale and selling a low-strength antenna support module, which could be mounted atop a mast. The low-strength unit was designed to be used singly or to allow at most two such modules to be stacked together. The module included a lower plate, an upper plate and a central post extending between the plates. The module was shown and described in the January 2001 EMS Wireless Product Catalog. The present inventors, however, have found the low-strength module to be less than ideal in high wind applications or other high strength applications.
Unfortunately, known antenna tower designs generally do not provide the strength to support more than a limited number of antenna panels or external attachments, such as flags, banners, signage and the like, combined with an aesthetically pleasing compact appearance. Further, they generally do not provide the strength needed to withstand harsh environmental stresses, in particular high wind, that are often encountered. This can be particularly important in certain regions, such as coastal areas.
In view of the above deficiencies of the prior art, there is yet a need for a compact antenna tower and support structure that is capable of accommodating more than a limited number of antennas or antenna panels. Further, there is a need for a compact antenna tower/support structure that is capable of supporting external attachments, such as flags, banners, signage and the like. Further, there is a need for such compact antenna tower/support structures to be capable of withstanding high winds. It is to the provision of such an antenna tower and support structure therefor that the present invention is primarily directed.